Inbox Search

Outlook's built-in search works fine when you remember the exact words. But what about that email from a recruiter last spring about a backend role, or the contract attachment your manager sent before the holidays? Inbox Search lets you find emails the way you actually remember them, by meaning rather than just keywords.

Type what you're looking for in plain English. Inbox Search understands intent, synonyms, and related concepts, so "quarterly budget approval" finds the email even if the original message said "Q3 spend sign-off." It combines semantic search with traditional keyword matching, so your results are both relevant and precise.

Your email never leaves your device

Most AI search tools send your messages to cloud servers for processing. Inbox Search doesn't. A small open-source AI model (33 MB) runs locally in your browser using WebAssembly and builds a private search index right on your machine. No external servers, no third-party AI services, and no email content transmitted anywhere.

How the search works

• AI semantic understanding matches meaning, not just words
• Keyword matching (BM25) handles exact terms, names, and IDs
• Reciprocal Rank Fusion blends both, so you get the strengths of each
• Results are ranked by relevance, with a one-click switch to sort by date

Power-user filters

• from: and to: narrow by sender or recipient
• folder: searches within a specific folder
• has:attachments finds emails with files
• Date ranges scope your search by time
• "Exact phrases" in quotes return literal matches
• A minus sign (-) excludes terms

You can mix filters with natural language in a single query. For example, vendor renewal questions from:legal has:attachments combines structured filters with semantic meaning at once.

It fits how you already work

Pin Inbox Search to the Outlook sidebar and it stays one click away while you read and reply to email. There's no separate app to open and no context switch.

Requirements

• Microsoft 365, or a personal, work, or school Microsoft account
• Outlook on Windows, Outlook for Mac, or Outlook on the web
• Internet connection on first use to download the AI model (cached after)

Who it's for

Knowledge workers, consultants, recruiters, salespeople, founders, lawyers, and researchers — anyone whose inbox holds important history that's hard to dig back out. It suits busy individuals and small teams alike. If you've ever lost ten minutes scrolling through search results and trying different keyword combinations, Inbox Search is built for you.

A few honest notes

The AI model is good but not perfect. Semantic search occasionally misses the mark, which is why keyword matching runs alongside it as a safety net. Initial indexing takes a few minutes depending on mailbox size, and the index updates as new mail arrives. The semantic model currently supports English only — other languages still work through keyword search, with broader language support planned.

Pricing

Free to use: unlimited keyword search and mailbox indexing, plus 5 AI finds a day. A find is only used when AI search surfaces an email and you open it. Pro removes the daily limit for €7.99/month or €79/year, and starts with a 7-day free trial. Subscriptions are handled by Polar and can be cancelled anytime from the add-in's Settings.

Install Inbox Search to make your inbox properly searchable, without giving up control of your email.